Commutator truing tool



Oct. 4, 1932. G. M. LINTELMANN 1,881,410

coMMUTAToP. TRUING Tool.

Filed June 12. 1928 5 f a 5 5 i Patented Oct. 4, 1932 STATES UWEv ' GEORGE III. LINTELMANN, OF SPOKANE, WASHINGTON, ASSG-NOR OF ONE-HALF T0 LOLA M. LINTELMANN, OF SPOKANE, WASINGTON and other electrical machines.

GOMMUTATOR 'Application filed June 12,

My invention relates to an improved commutator truing tool for use in truing up the surfaces of commutators for electric motors The tool is adapted for use as an attachment and provides a stationary abrasive for the rotating commutator as the latter is revolved or rotated under the power usually applied thereto. Means are provided whereby the tool may be applied to the commutator and supported from the motor casing after the cover has been removed from the latter, thus facilitating the operation of truing the commutator without the necessity for time and labor in removal of the motor from its casing.

As is well known the commutator, while in service, Vbecomes worn from frictional contact with the brushes, resulting in irregularities in the periphery of the commutator and consequent ineciency in the operation of the motor. By the utilization of the tool of my invention these uneven surfaces or irregularities are smoothed out and obliterated and the periphery of the commutator is trued to insure eflicient performance of its functions.

The tool or appliance is designed for use with various sizes of motors, and consists in certain novel combinations and arrangements of parts involving the construction and operation of the tool or appliance as will hereinafter be more fully set forth and claimed.

In the accompanying drawings I have illustrated one complete example of the physical embodiment of my invention wherein the parts are combined and arranged according to the best mode I have so far devised .for the practical application of the principles of my invention.

Figure 1 is a sectional View of a part of a motor casing of an electric machine, disclosing the commutator, and illustrating the application thereto of the appliance or tool of my invention.

Figure 2 is a perspective View of the appliance with the grinding or-abrasive tool omitted for convenience of illustration.

Figure 3 is a perspective view of the tool holder, detached.

Figure 4 is a view in side elevation of the tool carrier, detached.

TRUING TOOL 1928. serial 110.284,718.

vFigure 5 is a sectional detail view as at line 5-.5 of Figure 2.

Figure 6 is aview of one of the'two tie bolts having right and left hand screws.

Figure 7 is a perspective view of an adjustable. fastening block for use in adapting the vappliance to various sizes of motors or motor casings.

`Figure 8 is a view of the abrading tool or block carborundum stone.

Figure 9 is a perspective view of the complete abrading or grinding tool.

In order that the general assembly and arrangement of parts may readily be understood l have indicated in Figure l a portion of a conventional commutator C within thermotor casing M, the latter being fashioned with a iiange F about the manhole that permits access to the motor. The casing is provided with the usual cam lock G for the cover plate (which has been removed to accommodate the appliance) and an attaching or fastening lug H is shown on the flange F oppositeto the cam lock Gr.

The abrading tool as shown in Figures 8 and 9, and which is held with a resilient support in contact with and above the commutator for frictional contact therewith, consists of an abrading block or stone l of carborundum which is attached to the tool head 2 bymeans of an attaching flange or plate 3 and bolts 4. The head 2 is preferably rectangular in cross section and is Vadapted to be fittedinto acomplementaryholder 5, the head' being free to move, slightly, in a vertical plane within the holder, and of course the holder maintains the stone in position for frictional Contact on the top surface of the revolving commutator as the latter is turned over in usual manner.

By means of a pair of sockets 6,*located at diagonal points near the corners of the holder and at the extericrof its opposite sides, and a'pair of springs 7 partially en cased in thesoclrets and bearing on the diagonally opposite corners of the tool, the stone is heldvwith a resilient pressureagainst the surface to be ground.

Thetool and its holder are enclosed within a hollow, rectangularA carrierS which has a pair of diagonally opposite corners cut away at 9 to accommodate the sockets 6 ofthe holder, and the latter is adjustable in the carrier for the purpose of varying the tension of the springs and thereby varying the resiliency of the pressure on the tool.

The carrier is provided with a pair of threaded bosses 10 and the holder has a pair of alined, complementary bosses 11, the bosses 10 and 11 having respectively right and left hand screw threads therein. The carrier and holder are adjustably tied together by a pair of right and left hand tie bolts 12 having vcranlr handles 12', and it will be apparent that by turning these bolts the holder may be adjusted relatively to the carrier, .to vary the tension of the springs and thus vary the resilient pressure of the tool or abrading stone against the oommutator or surface to be ground. Y

The carrier has an open bottom, but closed top 13 and beneath the top at the upper edge of the two side walls of the carrier are fashioned a pair of complementary slots 14: through which a flat, supporting bar 15 is passed and from which the appliance or tool is suspended in stationary position. A pair y of clamp bolts 16 are passed through bolt holes inthe top plate 13 and through a selected pair of hole-s 17 in the supporting bar 15. lThe bolt holes 17 are arranged in two series so that the tool vmay be supported from various points within the length of the supporting bar, and the clamp bolts are passed through the selected pair of holes to hold the tool in desired position on the bar.

At one end of the bar it is fashioned with an attaching or fastening hook 18 which, as shown in Figure 1 is designed to fit under the lug I-I on the motor casing, and the other end 19 of the bar is provided with a flat spring 20 secured at its underside so that the spring may be slipped under the flange F of the casing with the end 19 over the top face of the iiange, and by means of Va Jfriction lug or shoulder 21 on the end 19'the snap lock or cam lock G of the casing cover is used to retain the bar inposition.

F or the purpose of accommodating the ap-v plianee to motors having smaller oasings, an adjustable, stepped, fastening block 22 is secured at the under side of the bar by means of Y bolt 23 that is passed through a selected hole 24- of a series of holes provided in the longitudinal center of the bar.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is The combination with a bar adapted to be supported above a commutator and having fastening means atits ends for at- Y tachment to a motor casing, of a slotted carrier-casing suspended from and slidable on the barn and fastening means therefor, a tool holder fitted in the casing and tie bolts se- GEORGE M. LINTELMANN.

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